Cartridge



C. E. SIMPSON CARTRIDGE 2 Sheets-Sheet l Filed NOV. 30, 1945 El'uTEnne :ET 51111135011 MKZm/wmmw C. E. SIMPSON CARTRIDGE `Fuly 11, 1950 2 Sheets-Sheet 2 Filed Nov. 50, 1945 Wn www u1 .m 5 E e c n E T m E Patented `Iuly 11, 1950 CARTRIDGE l Clarence E. Simpson, Springfield, Mass. Applicationl November 30, 1945, Serial No. 632,097

l M(Granted under the act of March 3, 1883, as

I amended. Aprilo, 1928; 370 0. G. 757) 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to an improved cary tridge for a firearm.

Numerous attempts have been made to actuate breech mechanisms of firearms by the set back of the cartridge primer. Some of these attempts have been fairly successful but ammunition prepared in such fashion to permit utilization of the set back of the primer for actuation of the firearm has been diflicult to manufacture. Improper seating of the primer, under or oversize primers,

and cocked primers added to the difficulty in obtaining reliable ammunition.

Accordingly, it is an object of this invention to provide an improvedcartridge for a firearm of the type wherein an element of the cartridge aceiect operation of the breech mechanism of the iirearm. Y'- A particular object of this invention is to provide an improve-d cartridge for projectiles of .60

caliber or larger. The specic nature of the invention as well other objects and advantages thereof will clearly vappear from av description of a preferred embodiment as shown in the accompanying drawings in which: -1

Fig. 1 is a fragmentary View `of a cartridge case shown partly in longitudinal section to illustrate the dowel pins contained in the base of such cartridge case. Fig. 2 is a fragmentary longitudinal sectional view'of a firearm showing the cartridge embody- Fig. 6 is a rear end elevational View showing the f locking surfaces in the barrel extension which are engaged by the locking lugs of the bolt.

Fig. 'Y is a fragmentary view in longitudinal section showing in enlarged detail the rearm actuating members in the battery position.

tuates a piston or tappet member which in turn .20

Fig. 8 is a top elevational view of the iirearm bolt showing the unlocking cam.

Fig. 9 is a cross sectional View taken along the lin-e 9-9'of`Fig. 3.`

Essentially this invention comprises the provision of two or more vent holes inthe base of a cartridge case and forcing in such vent holes hardened dowel pins. The sudden pressure developed within the cartridge case imparts a hammer-like blow to the dowel pins thereby driving such pins rearwardly'fto act upon a tappet or other actuating member which impartsa sudden momentum to the recoiling member of a rearm to effect unlocking thereof and to provide energy for the recoiling 'breech member to complete its cycle.

In Fig. 1 there is shown in assembled relation .a conventional 'cartridge embodying` this invention. Such cartridge comprises a case I Whiehis provided with an integral base portion 2. Inthe center of Asuch base portion there is provided an axial ash hole 3. The rear of such flash hole is enlarged as shown at 4 to receive a primer .5.

'luch primer is the conventional percussion type primer commonly utilized in present day'rearm cartridges.

In base portion 2 there is provided a plurality of horizontal holes 6 which communicate with the interior high pressure region of the cartridge. In the preferred application of this invention however only two such holes are provided as such number does not unduly reduce the cross-sectional area of such base portion. In each hole Ii there is forcibly inserted a pin 1. Thel pins I are preferably of hardened steel to better withstand the impact forces placed upon such pins, as will be presently described. When assembled to cartridge case I the ends of pins 'I are placed flush with the outside of base portion 2.

To better illustrate the function of this improved cartridge, such cartridge is placed in a chamber 8 of a barrel 9 of a iirearm I0 shown in Fig. 2. Firearm IIJ vessentially comprises a receiver I I, a bolt I and an inertia member I3. Inertia member I3 is arrangedA to bev driven forwardly on the counter-recoil stroke thereof by a driving spring I4. A cam Vmember I5 surrounds inertia member I3 and a pair of oppositely disposed cam tracks I 6 are provided on cam member I5 which are engaged by the opposite ends of a transverse pin II. Transverse pin I'I is mounted in inertia member I3, as shown in Figs. 2 and 9, to connect cam member I5 to inertia member I3. Bolt I2 is connected to cam member I5 by threads I8.

3 A plurality of equally spaced lugs I9 are provided on the forward end of bolt I2 about the periphery thereof as shown in Fig. 5. The lugs I9 engage suitable locking surfaces 2 provided in a barrel extension 2l which is secured to receiver II by threads 22. The rotation of bolt I2 by cam member I effects unlocking of bolt I2 from barrel extension 2|.

An axial hole 23 is provided in bolt I2.

face of bolt I2 is counterbored as shown at 2'4y to accommodate the base of cartridge case Ia A. second smaller counterbore 25 is provided adjacent counterbore 24 to accept a head 26L of' an actuator 21. Actuator 21 is'apiston-like member.y An aal hole 28 is provided in actuator 21 hav- The ing a configuration corresponding to thatnof aY lles: 6'is easily' overcome by the force of the powder. gases. It is desired to point lout here that in the' battery position'of boltY I2 head 26 f). actuator 2,1 does not lie against the bottom fjc'unterbore 25. Instead a space of about. 1/3'2'" or greater is leftbetween the bottom of; such hole andthe rear shoulder of thev head 26 of actuator 2,1.. Thuswhen pin` 1 strikes head 2B of actuator 2`.1, .s'1eli actuator is driven. rearwardly at' exticned relative to the amount of energy required to function the primer while heretofore the area of the primer was primarily determined by requirement-s of the cartridge for proper ignition.

I claim:

1. A cartridge yfor an automatic firearm having a primer andiA a piston mounted., on the base thereof independent of' said primer, said piston communicating with the interior high pressure region of such cartridge, said piston being movable rearwardly relative to the cartridge only under the forces developed by discharge of said cartridge.

2..A cartridge for a rearm having a, primer and a generally cylindrical member press fitted into ythe base thereof independent of said primer,

A said member communicating with the interior tr'eniely. high velocity,v whereupon such actuator sti'ikes inertia member I3 driving suchr inertia member. rearwardly. Y

y Aspin. I1 isin engagement with cam tracks I6 provided, n cam member I5, the4 rearward motion of inertia member I3 forces cam member I5 to i'otateLthereby` eie'cting yrotation of 'bolt VI Zto disengage lugs IS from barrel extension 2l., thus permitting bolt I2 to travelrearwardly assisted by residualgas .pressure in the chamber 8j to complete its. recoil stroke.l .,Eipriiig I4 then biases inertia in'er'nbe'rl I3arid bolt I2 forwardly tobattery positinwherepon' another cartridge is introduced into chamber Blof barrel' 9.

From-th, foregoing description it is: apparent that ther` improved cartridge herein described positively actuates the breech. mechanism ofa fire'- arm-.adapted to utilize such a cartridge. Further, a cartridge can be securely held in a fixedposition asset back of the cartridge isnot required, hence the head space of the firearm can be maintained-t. In addition, this improved cartridge is simple, and inexpensive to manufacture.

Fiallytheuse of the'piston-lile insertspermits ahardened steel-to be utilized for the actuating member in contrast.y to the soft deformable metalgrequired when-the primer functions asthe actuating memben Furthermore, the effective areafof the pistoninserts can be exactly proporhigh pressure region-of said cartridge, said member being movable rearwardly relative to the cartridge only under the forces developed by discharge of said cartridge.

3. In-'a cartridge adapted to actuate an operati'ng-y member of' aflr'earm, a. primer centrally lo.- cated in the base of the cartridge, a gas-actuated pistonf frieticnally mounted inl the base oi' the cartridge, independent of said-v primer, saidf pis'- ton lliavingv one end thereof directly adjacent theinteriorhighiprmsure region o'f the cartridge 'and the other end' arranged to contact the operating member' of the firearm when thecartridge is inserted? therein;A saidpiston being movable rearwardly relative to'-y the cartridge only? under the forces developed" in the nigh pressure region uponv the'- ds'char'ge ofthe cartridge thereby imparting-iii turni'ec'oil movement to the firearm operating member.

4f. In acartridge adaptedto actuate an operatingfrhe'inbei'l f' a firearm, a primer centrally located'inlthe-'base of the cartridge. arida plurality o'ij"V gas-actuated piston pins radially mounted about s'aid primer and independent thereof; each of said pins having one end thereof in direct communieation withthe' interior high pressure region of the ear'tiiidge and the other end adjacent the operating member of the firearm When-the cartridge-is inserted therein, 'Said-' pins being movable rearwardly relative tothe cartridge onlyunder the forces' developed inthe'hig'h pressure region `upon thediseharge of' the cartridge thereby imparting in turn recoil movement to the firearm operatingmember. v

CLARENCE'E. SIMPSCJII` REFERENCES CITED Thefollowing references arel of record in the lle of this patentzr UNITED STA-TES PATENTS 

